Description of problem:
I want install F14 i386 system with custom partition layout on two SATA disks:
- md0 (sda1+sdb1) mounted to /boot
- sda2 and sdb2 are normal swap partitions, no RAID
- md1 (sda3+sdb3) mounted to /
- md2 (sda4+sdb4) mounted to /mnt/os2
- md3 (sda5+sdb5) mounted to /home

I have just only one disk and want install system on degraded array, second disk will be added later.
Then I immediately (after anaconda start and start shell on tty2) run gdisk (from nfs volume, it was askmethod->nfs installation) and make required sdaX partition, then run mdadm and create relevant mdX RAID1 devices (as degraded).

Then switch back to anaconda GUI, select simple storage devices, and volumes custom layout. Anaconda rightly found and display mdX devices and allow me select them, click "Edit", then check off "Format as ..." and select mountpoint. This functionate fine - except for last md device:
When selecting them and clicking "Edit", error window appears saying
"For creating RAID device are needed at least two unused partition of type software RAID. First create at least two partitions of type 'software RAID', then select 'RAID' option again." (sorry for free translation, I install it in my native language)

As in my case last md disc isn't system disc, I was still able install F14, leaving md2 device unused, thus this problem isn't fatal.